Creative Commons provides free tools that let authors, scientists, artists,
and educators easily mark their creative work with the freedoms they want it to
carry. You can use CC to change your copyright terms from "All Rights Reserved"
to "Some Rights Reserved."
Creative Commons is an alternative to Copyright, it allows more use, a wider range of choices for distribution, reuse and attribution. You can go to the Creative Commons website choose among the options for how you'd like to share your work. The license can be applied to both works online and offline. There are books publish with the Creative Commons license. Flickr allows you to apply a license to all your photos, very handy for people looking for images to use, you can limit your search to only those you're allowed to use.